List out the disadvantages of database management systems.

Disadvantages of Database Management System (DBMS) are: High initial investment in hardware, software, training and installation facilities. Data Conversion is very large and cumbersome task in case of installing/upgrading new DBMS. DBMS is highly complex and require specific training of users. Database management systems require technical staff to maintain them and keep them running. Example Database Administrators (DBA), Application Programmers. While centralization reduces duplication, the lack of duplication requires that the database be adequately backed up so that in the case of failure the data can be recovered. This increases the potential severity of security breaches and disruption of the operation of the organization because of downtimes and failures. While data security system is a boon for using DBMS, it must be very robust. If someone can bypass the security system then the database would become open to any kind of mishandling. Regular backups are to be kept to avoid failure. Taking backup is a lengthy process and the computer system cannot perform any other job at this time.